Roadbed broom and bristle

ABSTRACT

A bristle element especially adapted for use in a broom machine for a railway roadbed or track. The bristle elements are replaceably mounted on a mandrel rotatable on a horizontal axis. The bristle elements have a core made of a bundle of parallel straight spring-steel splines or wires fixed together at one end in a detachable coupling and encased in a resilient sheath which binds the splines into mutually supporting relation and distributes flexing stress in them away from their fixed end.

United States Patent Kershaw et al.

[451 Mar. 21, 1972 [54] ROADBED BROOM AND BRISTLE [72] Inventors: John Knox Kershaw, Knoxville, Tenn.;

Edwin S. Pearce, Indianapolis, Ind.

[73] Assignee: The Marmon Group, Inc., Chicago, Ill. [22] Filed: Aug. 17, 1970 [21] Appl. No.: 64,266

Related U.S. Application Data [63] Continuation of Ser. No. 745,772, July 18, I968.

Dangremond et al.

3,228,053 1/1966 Horton et al ..15/183 3,237,232 3/1966 Holley ...l5/179 X 3,256,546 6/1966 Schmidt ...l5/l9l X 3,353,201 ll/1967 Horton et al ..15/198 X FOREIGN PATENTS OR APPLICATIONS 1,352,797 1/1964 France 15/183 754,953 8/1956 Great Britain ...l5/I83 166,724 l/l965 U.S.S.R. ..l5/I83 Primary Examiner-Peter Feldman Attorney-Hofgren, Wegner, Allen, Stellman & McCord ABSTRACT A bristle element especially adapted for use in a broom machine for a railway roadbed or track. The bristle elements are replaceably mounted on a mandrel rotatable on a horizontal axis. The bristle elements have a core made of a bundle of parallel straight spring-steel splines or wires fixed together at one end in a detachable coupling and encased in a resilient sheath which binds the splines into mutually supporting relation and distributes flexing stress in them away from their fixed end.

5 Claims, 5 Drawing Figures PATENTEDMAR21 1972 3,649,984

SHEET 1 UF 2 37 ,52 6o 52 O 31 W O INVENTORS JOHN KNOX KERSHAW EDWIN S. PEARCE ATTORNEYS ROADBED BROOM AND BRISTLE CROSS REFERENCE This application is a continuation of our prior co-pending application, Ser. No. 745,772, filed July 18, 1968.

The broom machine here shown is the subject of a co-pending application of John Knox Kershaw, Ser. No. 712,832, filed Mar. 13,1968, now US. Pat. No. 3,533,121.

BACKGROUND OF THE INVENTION This invention relates to a broom machine especially adapted for construction and maintenance work on a railway roadbed or track, as for dressing the surface of the ballast bed between and along the sides of the rails, and for leveling and distributing ballast over such bed.

Railway ballast comprises a thick layer of crushed limestone or similar material resting on a prepared base and in which the track cross ties are embedded and supported. The ballast bed is shaped to have a generally horizontal top face over the lengths of the ties, that is, between the rails and alongside the rails and to have sloped banks at and beyond the ends of the ties. Desirably, the top surface of the ballast is level with or slightly below the top faces of the ties, and the ties and rails should be free of loose ballast and debris.

Both in maintenance and in original construction of the roadbed, new ballast is dumped onto the roadbed from cars and is roughly distributed by a blade device such as a plow or moldboard. lt is not possible, however, for such a blade device to produce the desired finish condition in which the ballast is level with or slightly below the tops of the ties. A brush or broom implement can produce the desired distribution and surface condition. The sweeping of ballast, however, imposes a severe load on the broom so that brooms are subject to heavy wear and short life.

As has been suggested by the prior art, we constructed a broom in which the bristles were lengths of steel cable removably fastened to the mandrel or drum of the broom and encased in sections of heavy-duty hose to control fraying of the cable. With that broom, it was found that in ballast dressing operations, such steel cable bristles would last only about two hours and would sweep less than five miles of track before requiring replacement. It took two men two full days to replace the bristles. With such steel-cable bristles, the broom gave less than one man-day of service for each four man-days of repair, and this was economically impractical. The new bristle of the present application provides a broom capable of greatly prolonged operation. In comparative tests on a test machine, such new bristle lasted more than 30 times as long as the old steel-cable bristles.

SUMMARY OF THE INVENTION A broom implement embodying the present invention may comprise a frame which in operation extends transversely with respect to the direction of movement of the implement, and which carries a rotary broom element rotatable on a transverse horizontal axis and ofa length sufficient to sweep the entire top surface of the railway ballast bed. The broom is driven by a suitable motor and may be rotatable in either direction for operation in either direction along the track. The broom comprises a central drum or mandrel which at longitudinally and circumferentially spaced points carries fixed mounting elements for the attachment of individual bristle elements. Each bristle element consists of a core, here shown as a bundle of straight, parallel spring-steel splines or wires, encased in a retaining and bend-distributing sheath and fixed at one end to a coupling adapted to be removably attached to the broom mandrel. The straight and parallel splines of each bundle are fixed together at the coupling end but are free of each other over the rest of their length, so that on flexure of the bristle, the splines flex together but independently. The bend-distributing sheath may be molded about the core and binds the splines into mutually supporting relation, and distributes the bending away from the fixed point of attachment. to prevent concentration of stress at that point of attachment. Preferably, the sheath is resiliently stiffer at the coupling end of the bristle and more flexible toward the free end of the bristle.

THE DRAWINGS The accompanying drawings illustrate the invention. In such drawings:

FIG. 1 is a vertical sectional view of a broom implement embodying the invention with such implement mounted in operative transverse position on the headblock of a prime mover vehicle such as shown in application, Ser. No. 7 12,832;

FIG. 2 is a horizontal sectional view taken on the line 2-2 of FIG. 1, showing the broom implement in plan with the top frame and cover removed:

FIG. 3 is an axial sectional view of a bristle in accordance with the invention in which the encasing sheath is formed from a pair of concentric sleeves;

FIG. 4 is a section on line 4-4 of FIG. 3; and

FIG. 5 is an axial sectional view of a bristle embodying the invention in which the bundle of splines is encased in a molded rubber sheath.

DESCRIPTION OF THE PREFERRED EMBODIMENT The apparatus shown in FIG. 1 comprises a prime mover 10 having traction wheels 12 and guide wheels 14 adapted to travel on the rails 16 of a standard railroad track. The rails 16 are supported on ties 18 laid in a ballast bed 20. The prime mover carries at its forward end a headblock assembly 30 in which a carrier 31 for the guide wheels 14 is mounted and which has hydraulic cylinders (not shown) for raising and lowering such carrier. The headblock also includes a pair of outer tubular guides 33 which slidably receive the end end posts 34 of a mounting frame 36 which may be raised or lowered by a pair of hydraulic cylinders 35 and which carries at its lower end a pair of spaced brackets 37 to which the broom implement frame is pivoted. The mounting frame 36 carries one or more sheaves 38 at the top, on which are wound cables 40 for supporting the overhanging end of the broom implement.

The broom implement 50 comprises a sturdy rectangular frame formed by outer side stringers 52 interconnected at their ends by end members 54. Inner stringers 56 extend between the end members 54 in inwardly spaced relation with the side stringers 52. Upwardly inclined beams 57 extend from the side stringers 52 to a top frame 58. The broom chamber is formed between the inner stringers 56 and is closed at the top by an arched cover 60 extending the full length of the frame. A broom mandrel 62 is journaled at its ends in bearings 64 carried by the end members 54, and the mandrel shaft 66 at one end carries a multi-groove pulley 68. The hydraulic motor 53 is mounted on the top frame 58 and drives a shaft 55 which carries a pulley connected by belts to the mandrel pulley 68.

The broom mandrel 62 carries a plurality of circumferentially spaced rows of spaced bristle elements 76 and 78. While other arrangements may be used, that shown in the drawings comprises eight rows, each containing 14 bristle elements. The rows are staggered to sweep substantially the full surface of the underlying roadbed. The bristle elements 78 which overlie the rails are short to sweep the top surfaces of the rails while the bristle elements 76 are longer, to sweep the face of the ties and the ballast bed. When the broom element is in operative position, the bristle elements 76 positively but barely sweep the top surfaces of the ties 16 supporting the rails, as indicated in FIG. 1, so that such rails will be cleared of loose ballast and the ballast between the rails will be brushed to a depth at least as low as the surface of the ties.

A bank of baffles 70 is mounted at the front and rear of the frame, and each bank is arranged in two groups, with the baffles of each group interconnected and arranged to be swiveled so that all may be inclined in one direction as shown at the top of FIG 2 or the two groups may be inclined in opposite directions as shown at the bottom of FIG. 2. The baffles 70 serve to deflect ballast thrown forward by the broom implement to shift it laterally of the roadbed.

A form of bristle found to have a long operating life in this ballast-sweeping operation is shown in FIGS. 3 and 4. The broom mandrel 62 carries an internally threaded stud 72 at each location of a bristle 76 or 78. Each bristle comprises a core 80 formed of a bundle of straight spring-steel wires or splines 82, the upper ends of which are spread and fixed in a block 84 of cast filler such as lead. Such block is seated in a coupling 86 which has an upper threaded end 88 engaged in the internal threads of a stud 72. The coupling 86 carries a flange 89 of hexagonal shape at the base of the threads 88 in position to abut the end of the stud 72 and to be turned by a wrench. The lower end of the coupling 86 forms a reduced nipple 90 extending along the core 80 and conveniently of progressively decreasing thickness toward its lower end. An inner sheath 92 consisting of a length of heavy-duty hose is threaded onto or otherwise fixed to the nipple 90, and extends to or substantially to the free end of the core 80. An outer sheath 94 surrounds the upper end of the inner sheath 90 and is clamped to the outer surface of the coupling 86 by a clamp 96.

The number of wires or splines 82 in the core 80 may be varied to obtain different degrees of flexibility or stiffness for the bristle element as a whole. Desirably, the core may comprise from say 30 to 45 spring-steel wires of from 12 to 16 gauge. In a preferred bristle, 36 wires of 14 gauge spring-steel wire were used. The composition of the wire may be selected to give the desired strength and resilience and to provide good wear resistance. One suitable steel composition is that identified as SAE 1010.

The wires or splines 82 of the core 80 are fixed at their upper ends in a common mounting block 84, but are otherwise free of each other so that they flex together but independently and slide on each other as the bristle isjflexed. The splines are held together in a bundle by the two sheaths 92 and 94 which produces a mutually supporting relation between the splines and serves to distribute the bending stress in the core 80 away from its point ofattachment to the rigid coupling 86.

The degree of bending of the bristles in operation of the broom may be controlled by adjusting the elevation of the broom implement with relation to the surface being swept. In a preferred arrangement, we have used a drum mandrel 62 of 6 inch outside diameter and proportioned substantially as shown in FIG. 3, with a total radius from the center of the mandrel to the end of the core 80 of 22 be inches, and have operated the broom at an elevation such that the end of the core would traverse an are passing through the upper corners of the ties 16. Each bristle element as it passes over the center of each tie, will then positively but lightly brush the entire face of the tie. The bristle elements will be flexed to a certain degree but not excessively in this relationship, and will give effective operation over a long life. The bristle elements described have given sufficient life to be economically satisfactory and feasible. With the arrangement shown, we find we are able to obtain at least one full week of service from a broom, and can replace all the bristles on such broom within a sufficiently short time to make continuous week-by-week operation practical.

In the modified bristle arrangement shown in FIG. 5, the mandrel 162 of the broom is provided with an externally threaded stud 172 at each location of a bristle. Each bristle comprises a core 180 like the core 80 of the previous modification and is formed ofa bundle of spring-steel wires of splines 182. These are secured at their upper ends in a block 184 of cast filler material such as lead, and such block is seated in a coupling member 186 which is secured to the stud 172 by an internally threaded collar 188 having a shoulder'which engages the peripheral edge of the coupling block 186. The lower end of the coupling member 186 carries a nipple portion 190 extending downward along the splines 182. About such nipple portion 190 and the core 180 there is molded a rubber sheath 192 which is relatively thick at its upper end and progressively decreases in thickness toward the free end of the bristle.

The thickness and composition of the molded rubber sheath is selected to provide good abrasion resistance to protect the wire or splines of the core 180, to add stiffness to the bristle at broom implement 50 is adjusted so that the ends of the bristles sweep the roadbed surface to the desired depth, preferably with a light sweeping action across the top surfaces of the ties 18.

As the broom implement moves forward, with the broom rotating as described, the bristles sweep the roadbed surface to clear it of loose ballast and to throw such ballast forward into the baffles 70. Such baffles deflect the loose ballast to the side, to remove them from the path of the broom. If the deflection is not sufficient on the first throw, the ballast will be picked up again by the broom from where it fell, and will again be thrown forward into the baffles and deflected further, until it is deflected from the path of the broom. In this operation, the bending in the splines 82 or 182 of the bristles is distributed over the length of the splines and away from their point of attachment to the rigid coupling, by the action of the surrounding sheath and by the support given to each spline 82 or 182 by the other splines of the bundle. Bristles in accordance with the present invention are found to have a long effective life sufficient to make the broom practical and economical in this relatively severe service of spreading loose ballast on a railway roadbed.

The broom is effective for finishing distribution of loose ballast as described. It also has other uses, for example for sweeping an established railway roadbed for maintenance and to remove weed growth. It is also useful in other applications besides railway applications, for example in sweeping roadways, runways, and the like.

We claim:

l. A bristle element adapted for use on a roadbed broom, comprising a bristle core composed of a bundle of straight spring-steel splines in'parallel axial relation,.f1xed together at one end and relatively slidable with respect to each other over the remainder of their lengths when the bundle is bent,

mounting means connected to the fixed end of the bundle of splines for mounting the bristle element to a bristle support,

a flexible tubular sheath secured to the fixed end of the bundle and extending therefrom toward and substantially to the free end of said core,

said sheath binding the splines together to cause the same to flex together over substantially their entire length when the bristle element is bent,

said sheath being formed of resilient material and being of greatest thickness and stiffness adjacent the fixed end of the splines and of decreasing thickness and stiffness toward the free end of the splines and thereby resiliently supporting said bundle of splines against flexure adjacent the fixed end thereof and providing resilient support thereto distributed over substantially the entire length of the bundle of splines and decreasing from the fixed end thereof to the free end thereof.

2. A bristle element as in claim] in which said sheath is in the form of a molded sheath molded about the bundle of splines, thickest at the fixedend of the core and extending with progressively decreasing thickness toward and substantially to the free end of the bristle element.

3. A broom element adapted for use on a roadbed broom comprising a core composed of a bundle of flexible core elements in parallel relation, fixed together at one end and relatively movable axially with respect to each other over the remainder of their length when the bundle is bent, mounting means connected to the fixed end of the bundle for mounting the broom element to a support, a flexible tubular sheath secured to the fixed end of the bundle and extending therefrom toward and substantially to the free end of said bundle said sheath binding the flexible core elements together to cause the same to flex together over substantially their entire length when the broom element is bent, said sheath being formed of resilient material and being of greatest thickness and stiffness adjacent the fixed end of the bundle and of decreasing thickness and stiffness toward the free end of the bundle and thereby resiliently supporting said bundle of core elements and providing minimum flexure thereof adjacent the fixed end thereof and resilient support distributed over substantially the entire length of the bundle and decreasing from the fixed end thereof to the free end thereof.

4. A broom element adapted for use on a roadbed broom,

I comprising an elongated body having a fixed end and extending therefrom to a free end, mounting means connected to the fixed end for mounting the same to a rotatable support to position the free end for sweeping action as the support is rotated,

said body having an outer molded sheath portion of rubber or like resilient material, and having an inner core portion including 31 plurality of flexible core elements secured at their inner ends to said mounting means and extending longitudinally through said sheath,

said broom element being adapted to flex resiliently from its fixed end to its free end in the sweeping action of its free end,

the inner end of the body being of greatest thickness and stiffness adjacent its fixed end and of decreasing thickness and stiffness toward its free end,

said sheath and core portions interacting to support the said elongated body over substantially its entire length in such flexure and to distribute the flexure over the length of the body with minimum flexure at the fixed end of the body and progressively decreasing flexure toward the free end thereof.

5. A broom element adapted for use on a roadbed broom,

comprising an elongated body having a fixed end and extending therefrom to a free end, mounting means connected to the fixed end for mounting the same to a rotatable support to position the free end for sweeping action as the support is rotated,

said body having an outer molded sheath portion of rubber or like resilient material, and having an inner flexible core portion adapted to resist elongation, said core portion being secured at its inner end to said mounting means and extending longitudinally through said sheath,

said broom element being adapted to flex resiliently from its fixed end to its free end in the sweeping action of its free end,

the inner end of the body being of greatest thickness and stiffness adjacent its fixed end and of decreasing thickness and stiffness towards its free end,

said sheath and core portions interacting to support the said elongated body over substantially its entire length in such flexure and to distribute the flexure over the length of the body with minimum flexure at the fixed end of the body and progressively decreasing flexure toward the free end thereof. 

1. A bristle element adapted for use on a roadbed broom, comprising a bristle core composed of a bundle of straight spring-steel splines in parallel axial relation, fixed together at one end and relatively slidable with respect to each other over the remainder of their lengths when the bundle is bent, mounting means connected to the fixed end of the bundle of splines for mounting the bristle element to a bristle support, a flexible tubular sheath secured to the fixed end of the bundle and extending therefrom toward and substantially to the free end of said core, said sheath binding the splines together to cause the same to flex together over substantially their entire length when the bristle element is bent, said sheath being formed of resilient material and being of greatest thickness and stiffness adjacent the fixed end of the splines and of decreasing thickness and stiffness toward the free end of the splines and thereby resiliently supporting said bundle of splines against flexure adjacent the fixed end thereof and providing resilient support thereto distributed over substantially the entire length of the bundle of splines and decreasing from the fixed end thereof to the free end thereof.
 2. A bristle element as in claim 1 in which said sheath is in the form of a molded sheath molded about the bundle of splines, thickest at the fixed end of the core and extending with progressively decreasing thickness toward and substantially to the free end of the bristle element.
 3. A broom element adapted for use on a roadbed broom comprising a core composed of a bundle of flexible core elements in parallel relation, fixed together at one end and relatively movable axially with respect to each other over the remainder of their length when the bundle is bent, mounting means connected to the fixed end of the bundle for mounting the broom element to a support, a flexible tubular sheath secured to the fixed end of the bundle and extending therefrom toward and substantially to the free end of said bundle said sheath binding the flexible core elements together to cause the same to flex together over substantially their entire length when the broom element is bent, said sheath being formed of resilient material and being of greatest thickness and stiffness adjacent the fixed end of the bundle and of decreasing thickness and stiffness toward the free end of the bundle and thereby resiliently supporting said bundle of core elements and providing minimum flexure thereof adjacent the fixed end thereof and resilient support distributed over substantially the entire length of the bundle and decreasing from the fixed end thereof to the free end thereof.
 4. A broom element adapted for use on a roadbed broom, comprising an elongated body having a fixed end and extending therefrom to a free end, mounting means connected to the fixed end for mounting the same to a rotatable support to position the free end for sweeping action as the support is rotated, said body having an outer molded sheath portion of rubber or like resilient material, and having an inner core portion including a plurality of flexible core elements secured at their inner ends to said mounting means and extending longitudinally through said sheath, said broom element being adapted to flex resiliently from its fixed end to its free end in the sweeping action of its free end, the inner end of the body being of greatest thickness and stiffness adjacent its fixed end and of decreasing thickness and stiffness toward its free end, said sheath and core portions interacting to support the said elongated body over substantially its entire length in such flexure and to distribute the flexure over the length of the body with minimum flexure at the fixed end of the body and progressively decreasing flexure toward the free end thereof.
 5. A broom element adapted for use on a roadbed broom, comprising an elongated body having a fixed end and extending therefrom to a free end, mounting means connected to the fixed end for mounting the same to a rotatable support to position the free end for sweeping action as the support is rotated, said body having an outer molded sheath portion of rubber or like resilient material, and having an inner flexible core portion adapted to resist elongation, said core portion being secured at its inner end to said mounting means and extending longitudinally through said sheath, said broom element being adapted to flex resiliently from its fixed end to its free end in the sweeping action of its free end, the inner end of the body being of greatest thickness and stiffness adjacent its fixed end and of decreasing thickness and stiffness towards its free end, said sheath and core portions interacting to support the said elongated body over substantially its entire length in such flexure and to distribute the flexure over the length of the body with minimum flexure at the fixed end of the body and progressively decreasing flexure toward the free end thereof. 